1640s. Martin Kalinowski, and Chernihiv Governor dipole crown hetman of the Commonwealth, is building a stone castle in Sidorov.

Place chosen for the construction of fortifications on the elongated plateau high hill. With three sides (north-east, north-west and south-west) hill keeps flowing river channel Suhodol, providing additional future artificial strengthening natural defenses. Perhaps once the water level in the river was raised artificially. On the floor (south-east, the most vulnerable) party was dug ditch separated the cape with fortifications from the main body of the river bank. Over the moat was mounds. Good protection of the castle gave moorland, the middle of which stood the castle hill.

The material for the construction of the castle served as sandstone and limestone. Structure Sidorovsky castle has no direct analogues in Ukraine. The castle has an elongated shape dictated by the configuration of the elongated hill. The length of the castle complex is much greater than its width. Bailey stretched along the axis of the north-west - south-east for a distance of about 180 meters, while the width of the castle (the distance between two parallel castle walls) along the axis of southwest - northeast ranged from 30 to 40 meters.

Castle courtyard formed by two long walls of the fortifications that stretched almost parallel to each other. In place of the extremities of the castle complex parallel walls create sharp hall, converge at an acute angle. Both crease is flanked on two sides by powerful Basteja. This fortification technique (acute-angled arrangement of the crease walls flanking it Basteja) was typical of Podolsk defense architecture period 16 - the first half of the 17th centuries. This technique, for example, was used during the construction of the deputies in Buchach, Terebovlya, Valley (Jani) and other fortifications. The walls of the castle were Sidorovsky 2 bunk (?) - In the lower tiers were arranged casemated room.